In various applications of image processing or more generally of data processing, it is desired to convert an image resulting from a horizontal line scanning into an image resulting from a vertical saw tooth scanning into image stripes. Thus, as illustrated in FIG. 1, considering an image comprising successive lines of N image elements (pixels), each of which corresponds to a data word, it is desired to carry out a saw tooth reading into stripes of M lines, as illustrated in FIG. 1.
The most conventional way for realizing such a conversion consists in using two RAM memories each having the size of a stripe of MN data. The data corresponding to the first line scanning are stored in the first memory, and then are read in the desired order of the saw tooth scan into stripes while the data of the next stripe are written in the other memory, and so on, the two memories are alternatively read and written.
This method has the obvious drawback of requiring two memories with their independent addressing systems.
The invention provides for using a single memory of MN words for realizing this operation and also provides for a circuit permitting automatic supply of addresses, wherein data will be simultaneously read and written in selected memory cells.